Using a cylinder wrap for your hot water cylinder to minimise heat loss will help reduce your power bill by up to 10%. Older hot water cylinders are notorious for losing heat. Check for a grading on the side of your cylinder. If it’s A grade, then it should be fine. Or touch the side of the cylinder and if you feel any warmth, you’ll need a wrap to help retain the heat. Also make sure pipes to and from the cylinder are covered also. Call your local hardware store and they’ll be able to recommend a wrap and show you how easy it is to install.